I have written a bunch of (A)GPL code too and I'm 100% supportive of AI learning from it.
But it begs the question why you chose (A)GPL instead of a permissive license in the first place. If you are OK with people training and using LLMs on top of your work not giving users the right to inspect and modify, you must have logically been OK with it before. The existence of LLMs or even AI is irrelevant to your position.
Look at consent in sex and how long it took to make everyone accept it's something you need to have sex with someone. Some places are still not there yet.
I firmly believe using other people's work should require the same level of consent.